public bool TryDequeue(ThreadPoolWorkQueueThreadLocals tl, out WorkItem workItem)
{
WorkStealingQueue localWsq = tl.workStealingQueue;
if ((workItem = localWsq.LocalPop()) == null && // first try the local queue
!workItems.TryDequeue(out workItem)) // then try the global queue
{
// finally try to steal from another thread's local queue
WorkStealingQueue[] queues = tl.workQueue.workStealingQueues.Queues;
int c = queues.Length;
Debug.Assert(c > 0, "There must at least be a queue for this thread.");
int maxIndex = c - 1;
int i = tl.random.Next(c);
while (c > 0)
{
i = (i < maxIndex) ? i + 1 : 0;
WorkStealingQueue otherQueue = queues[i];
if (otherQueue != localWsq && otherQueue.CanSteal)
{
var ignoredMissedSteal = false;
workItem = otherQueue.TrySteal(ref ignoredMissedSteal);
if (workItem != null)
{
break;
}
}
c--;
}
}
return workItem != null;
}
public void Enqueue(WorkItem callback, bool forceGlobal)
{
ThreadPoolWorkQueueThreadLocals tl = null;
if (!forceGlobal)
tl = ThreadPoolWorkQueueThreadLocals.threadLocals;
if (null != tl && tl.workQueue == this)
{
tl.workStealingQueue.LocalPush(callback);
}
else
{
workItems.Enqueue(callback);
}
EnsureThreadRequested();
}
internal bool LocalFindAndPop(WorkItem callback)
{
ThreadPoolWorkQueueThreadLocals tl = ThreadPoolWorkQueueThreadLocals.threadLocals;
return tl != null && tl.workStealingQueue.LocalFindAndPop(callback);
}
